Pick the active voice of the following sentence: This word cannot be uttered by a sane man.

In the passive sentence, this word receives the action, while a sane man does the action. To change it into active voice, bring a sane man to the front and keep the meaning of cannot unchanged. This word cannot be uttered by a sane man. becomes A sane man cannot utter this word. Option 1 changes "cannot" to past tense. Option 2 changes "cannot" to "will not". Option 3 changes "this word" to "the word". Therefore, Option 4 is correct.